Method and apparatus for applying a false twist to yarns

ABSTRACT

A false twist is applied to a continuously advancing yarn by tangential contact of a first run of the yarn with a series of yarn flights that intersect and rotate the first run of yarn by frictional contact therewith. The yarn passes around a plurality of freely rotatable rollers and forms a series of yarn flights which intersect and frictionally contact the first run of yarn to apply a false twist thereto.

United States Patent 91 [111 3,831,365

Smith Aug. 27, 1974 [5 METHOD AND APPARATUS FOR 3,035,399 5/1962 'Scragg .1 57177.3 x

- APPLYING A FALSE TWIST o YARNS 3,103,097 9/ 1963 Meili et al 57/77.4

Inventor: Joseph F. Smith, 1407 Hobbs Rd.,

Greensboro, NC. 27410 Filed: Oct. 26, 1973 Appl. No.: 410,230

US. Cl. 57/77.4, 57/34 HS, 57/157 TS Int. Cl. DOlh 7/92, D02g 1/04 Field of Search 57/77.3, 77.45, 51, 51.6,

57/157 R, 157 T5, 34 R, 34 HS References Cited UNITED STATES PATENTS 5/l962 Biggers 57/77.3 X

Primary ExaminerDonald E. Watkins ABSTRACT A false twist is applied to a continuously advancing yarn by tangential contact of a first run of the yarn with a series of yarn flights that intersect and rotate the first run of yarn by frictional contact therewith. The yarn passes around a plurality of freely rotatable rollers and forms a series of yarn flights which intersect and frictionally contact the first run of yarn to apply a false twist thereto.

13 Claims, 11 Drawing Figures PATENTED M22 3L8$1L365 I W Ill ulllllllllll PATENTEUAUBNIQM 3.831 365 aim-2w FIG.8

METHOD AND APPARATUS FOR APPLYING A FALSE TWIST TO YARNS BRIEF SUMMARY AND OBJECTS OF THE INVENTION This invention relates to the false twisting of yarn by frictionally engaging and rotating a length of running yarn by a series of flights of the same continuous traveling yarn.

Various processes and apparatus are known for imparting a false twist to a yarn. A conventional system utilizes a tube or spindle which is driven by a belt or rollers. However, the rotation of the yarn is directly related to the speed which can be imparted to the tube. Twist also has been applied to yarn by direct frictional contact with driven, rotating surfaces, as disclosed for example in US. Pat. Nos. 3,668,853; 3,495,39l and 3,345,811, and flexible belts, as disclosed in US. Pat. No. 3,103,097. However, in each of the above-noted examples, a power source is required for driving the rollers, belts, etc.

In the present invention, a false twist is applied to yarn by passing a selected run of the yarn through an opening or channel defined by a plurality of intersecting flights of the same yarn. The yarn flights are generally normal to the selected yarn run and pass around a plurality of guide elements. In the broadest aspect, the guide elements may be two or more fixed guides of ceramic or polished construction to facilitate movement of yarn thereover with minimum resistance. Preferably, the guide elements consist of freely rotatable rollers around which the yarn passes. An S or Z twist may be applied to the selected yarn run depending upon the particular manner in which the yarn is wrapped about the guide means. Preferably, the yarn is wrapped about the guide means such that'the yarn flights move outwardly due to centrifugal forces and at an intersection of flights, the flights tend to grip the yarn within the channel more tightly.

Four guide rollers may be utilized with two yarns for frictionally twisting and applying simultaneously a Z twist to one yarn and an S twist to the other yarn. The two yarns are wound about the guide means to form a plurality of flights defining two separate yarn channels.

Still another object of the invention is the provision of a system for false twisting continuous running yarn by frictionally engaging a first displaceable section with a series of sections substantially nonnal to the first displaceable section.

Other objects and advantages of the invention will become apparent when considered in view of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic front elevational view of an apparatus for treating thermoplastic yarns and incorporating the false twist applying apparatus of the present invention;

FIG. 2 is a side elevational view of the apparatus of FIG. 1;

FIG. 3 is a schematic, front elevational view similar 0 to FIG. 1 utilizing two supply packages and a false twist apparatus for simultaneously twisting two yarns;

FIG. '4 is an enlarged top plan view of the false twist applying apparatus of FIGS. 1 and 2 and utilizing three rollers for guiding the yarn;

FIG. 5 is a side elevational view of the structure of FIG. 4;

FIG. 6 is a schematic, perspective view of the three guide rollers of FIGS. 4 and 5 and illustrating the yarn path between and around the rollers;

FIG. 7 is an enlarged, plan view of the intersection of three yam flights frictionally gripping therebetween and rotating a running length of yarn moving normal to the yarn flights;

FIG. 8 is an enlarged, cross-sectional view of one of the guide rollers and illustrating the yarn guide grooves therein;

FIG. 9 is a schematic, top plan view of a modified embodiment of the false twist applying apparatus of the present invention utilizing four rollers for simultaneously applying an S twist and a Z twist to two yarns;

FIG. 10 is a schematic side elevational view of the four roller arrangement of FIG. 9; and

FIG. 11 is an enlarged plan view of the intersecting yarn flights defining two separate and distinct channels, each channel for receiving a yarn to be twisted.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawing and particularly to FIGS. 1 and 2, a portion of a conventional yarn treating machine is illustrated, which would include a frame, motor drive mechanism, yarn guides, etc. A plurality of the units as shown by FIGS. 1 and 2 may be mounted in side-by-side relation on both sides of the frame.

In the embodiment of FIGS. land 2, yarn Y is directed from a supply package P of thermoplastic yarn to be treated, over lower feed rolls F-l, through a conventional heater H, through the false twist apparatus FT of the present invention, over the upper feed rolls F-2 and to a take-up package W. The speeds of the yarn feed rolls F-l and F-2 may be controlled to obtained a selected yarn condition in the heat-twist zone 2. The yarn is positively drawn through the false twist apparatus FT by the feed rolls F-2. The yarn is wound upon the package W by a conventional winding assembly including a yarn traverse means. Suitable tensioning' and guiding means may be provided, as required.

In the embodiment of FIGS. 1, 2 and 4-8, the friction twisting apparatus incorporates three rollers 20, 22 and 24 mounted in a triangular relationship upon a plate 26. The support plate 26 is provided with an opening for receiving a ceramic guide 28 for passage of the yarn Y therethrough. Also supported upon the plate 26 is a guide assembly 30 including a first guide 32 mounted above the rollers 20-24 upon an arm 34 and a second guide 36.

Preferably the rollers 20-24 are of substantially the same diameter and length and each includes a sheave 40 and shaft 42 freely rotatably mounted upon a bearing housing 38, FIG. 8, by ball bearings 44. Alternatively, the rollers may be supported by roller bearings, gas bearings, etc. The bearing housings 38 are all secured to one side of the plate 26 by suitable fasteners 46. The fasteners permit lateral adjustment of the rollers 20-24 relative to each other and preferably the axis of the rollers define an equilateral triangle.

The outer periphery of each roller sheave 40 is provided with a plurality of side-by-side annular grooves 48 of equal size. The grooves are of such a size and configuration to receive one or more strands of yarn.

The yarn Y, to have a false twist applied thereto, emerges from the heater H and is directed upwardly through guide 28 to the upper guide roller or wheel 32. From guide 32 the yarn is directed downwardly to the guide 36 and to a groove 48 within the lower portion of roller 22. The yarn passes around roller 22 and extends a first flight Yl to a groove 48 in roller 24, around roller 24 and in a second flight Y2 to roll 20, around roll 20 and in a third flight Y3 back to the roll 22. Preferably in the first series of flights Yl, Y2, Y3, the yarn is received within the lowermost groove 48 of each roll 20, 22 and 24. As can be observed most clearly by FIG. 5, the rollers 20, 22, 24, while of the same size, preferably are staggered vertically. The yarn Y is continuously led from thelowermost grooves in the rollers upwardly within the roller grooves in a series of yarn flights, as shown by FIG. 6. The rollers are staggered such that, for example, the grooves 48 of roller 24 are spaced vertically upwardly approximately 0.030 inches with respect to the grooves of the roller 22 and the grooves of roller 20 are spaced vertically upwardly approximately 0.030 inches above the grooves of roller 24. With this arrangement the yarn Y follows a generally helical path from the lowermost groove of roller 22 until yarn Y-4 emerges from the uppermost groove 48 of roller 20 and continues to the upper feed rolls F-2. The number of grooves 48 in the rollers 20, 22, 24 may vary and the yarn need not be necessarily positioned in every groove. In a preferred embodiment, the rollers are provided with twenty grooves 48 such that yarn Y forms 20 series of flights Yl, Y2, Y3.

Referring to FIG. 7, each series of yarn flights Yl, Y2, Y3 intersect to define a minute triangular crosssectional space or channel 50 through which a yarn run YS is directed. The yarn run YS is generally parallel with the parallel axes of rollers 20, 22, 24 and extends from ceramic guide 28 to the upper guide 32 so that each of the yarn flights Yl, Y2 and Y3 uniformly contacts the yarn run Y-S.

The intersecting yarn flights Yl, Y2, Y3 pass tangentially to the yarn run (-5 so that rotation is im parted to the yarn YS. As shown by FIG. 7, the directions of movement of the yarn flights are indicated by the arrows for applying a counterclockwise rotation to the yarn YS. An S or Z twist may be applied to the yarn YS depending upon whether the yarn is wound around the rollers -24 in a clockwise or counterclockwise direction. For example, the yarn is wrapped about rollers 20-24 in a clockwise direction, as shown by FIGS. 4, 6 and 7, resulting in a counterclockwise twist being applied to the yarn. It is to be noted that centrifugal forces applied to the yarn flight of each series tend to urge the flights tighter against the yarn run YS having twist applied thereto. The centrifugal forces applied to the flights by passing the flights around two adjacent rollers tend to throw the yarn flights outwardly adjacent the intersection point thereby tending to reduce the size of the channel 50 and grip more tightly the yarn Y5. The series of yarn flights, for example, 20 in a preferred embodiment referred to above, provides sufficient contact of the flights with the run Y5 to rotate the yarn Y-5 and apply the selected turns per inch thereto, depending upon the speed at which the yarn is drawn through the twisting apparatus FT by the feed rolls F-2.

Due to the helical configuration of yarn about rolls 20-24 from the lower grooves to the upper grooves, the series of yarn flights tend to assist the displacement of the yarn Y-5 upwardly within the channel 50 by gripping and lifting the yarn. However, by altering the guide assembly 30, yarn may be directed through the false twist assembly FT from the upper grooves to the,

lower grooves of the rollers 20-24.

In the embodiment of FIGS. 3 and 9-11, two yarns are directed simultaneously by four rollers such that an S twist is applied to one yarn while a Z twist is applied to the other yarn. The yarns X, V are drawn from separate packages P, P, through a generally common path of heater I-I, false twist applying apparatus FT, and wound in parallel fashion upon take-up package W. Alternatively, the yarn X, V could be wound upon separate winding packages. Feed rolls F--l and F-2 control the yarn movement substantially as described in the embodiment of FIGS. 1, 2 and 4-7.

Four yarn guide rollers 52,54, 56 and 58, similar to the rollers 20-24 of FIGS. 5 and 8, are mounted upon a plate or disk 26, and the two yarns X, V are directed through the ceramic guide 28 around guides 32 and 34 into the lower groove 48 of roller 52. From roller 52, the two yarns X, V pass around rollers 54, 56 and 58 a plurality of times until the twisted yarns exit from the twisting device. As shown by FIGS. 9 and 11, the two yarns X, V are directed from roller 52 to roller 54 in a first flight XI, Vl, from roller 54 to roller 56 in a second flight X2, V2, from roller 56 to roller 58 in a third flight X3, V3, and back from roller 58 to roller 52 in a fourth flight X4, V4 and progresses upwardly within the roller grooves 48 fonning a series of flights until the yarns exit at X5, VS between rollers 54 and 58. Each series of flights X1, V1; X2, V2; and X4, V4 intersect defining a generally triangular channel 60 and encompass yarn V for applying clockwise rotation thereto, as shown by FIG. 11, and yarn flights X2, V2; X3, V3; and X4, V4 intersect and define a second generally triangular channel 62 having the yarn X passing therethrough.

Yarn X is rotated counterclockwise, as shown. Again, the number of yarn flight series and the particular manner of guiding the yarns around the rollers 52-58 may vary, as described with respect to the embodiment of FIGS. 4-6, depending upon the desired results. The yarns, having opposite twist applied thereto, are directed to feed rolls F-2 and may be wound separately or upon a common package.

The intersecting flights of yarns in both of the embodiments illustrated substantially completely frictionally encompass the yarn run having twist applied thereto and the series of yarn flights imparts a unidirectional rotation and a substantially constant twist to the yarn with minimum slippage.

The rollers -24 and 52-58 are freely rotatable with respect to the support plate 26, rotation being imparted thereto only by frictional contact with the yarn which is drawn through the twisting apparatus PT by the feed rolls F2.

The number and location of rollers or guides employed, the speed at which the yarn is drawn around the rollers, the number of yarn flights, etc., may vary depending upon the desired results.

I claim:

1. The method of false twisting advancing yarns comprising; directing a first run of an advancing yarn longitudinally in a prescribed path, directing the advancing yarn downstream of the first run in a selected pattern to define a plurality of intersecting yarn flights in frictional engagement with the first run of yarn, and displacing the intersecting yarn flights in prescribed directions for imparting a rotational force to the first yarn run.

2. The method as recited in claim 1, wherein the intersecting yarn flights are substantially normal to the first run of advancing yarn.

3. The method of claim 1, wherein the yarn is directed in a selected pattern to form spaced series of intersecting yarn flights. x

4. The method as recited in claim 1, wherein the yarn flights intersect to form a triangle and the first yarn run passes through the triangle.

5. The method of claim 3, wherein the spaced series of intersecting yarn flights apply rotational and longitudinal forces to the first run of yarn.

6. The method of claim 1, and further applying a force longitudinally of the yarn downstream of yarn forming the selected pattern for directing the yarn through the selected pattern to impart a unidirectional rotation to the yarn forming the first run.

7. An apparatus for applying a false twist to an advancing textile yarn comprising, support means, a plurality of elongated elements mounted in spaced, generally parallel relation upon said support means and each element having a surface region for frictionally contacting the yarn, means for directing an advancing yarn in a first run in spaced relation to and generally parallel to the axes of said elongated elements and for guiding the yarn from the first run in a path into contact with the surface region of one of said elongated elements, said elongated elements being selectively positioned such that yarn is directed thereabout in a plurality of yarn flights with the yarn flights intersecting to define a channel for passage of the first run of yarn, said first run of yarn being substantially normal to the yarn flights, and at least a plurality of yarn flights frictionally engaging the first yarn run to impart unidirectional rotary movement thereto upon advancement of the yarn directed about the elongated elements.

8. An apparatus for applying a false twist to a yarn as recited in claim 7, wherein said elongated elements comprise freely rotatable rollers.

9. An apparatus for applying a false twist to a textile yarn as recited in claim 8, wherein the surface region of each roller is provided with a plurality of yarn receiving annular grooves, said yarn being wound around said rollers to form a series of intersecting yarn flights.

10. An apparatus for applying a false twist to a yarn as recited in claim 9, wherein the yarn progressively moves from the lowermost to the uppermost grooves of said rollers thereby facilitating longitudinal displace ment of the yarn first run.

11. An apparatus for applying a false twist to a yarn as recited in claim 7, wherein a plurality of advancing yarns are directed in spaced parallel runs and around said elongated elements with the intersecting yarn flights defining a plurality of channels, the yarn being received in each channel.

12. An apparatus for applying a false twist to a yarn as recited in claim 1 1, wherein one yarn with a channel has an S twist applied by intersecting yarn flightsand another yarn within a second channel has a Z twist applied thereto by intersecting yam flights.

13. An apparatus for applying a false twist to an advancing textile yarn as recited in claim 7, and further including means for applying a longitudinal force to the yarn for drawing the yarn about the elongated elements to impart a torque to the first run of yarn by said yarn 

1. The method of false twisting advancing yarns comprising; directing a first run of an advancing yarn longitudinally in a prescribed path, directing the advancing yarn downstream of the first run in a selected pattern to define a plurality of intersecting yarn flights in frictional engagement with the first run of yarn, and displacing the intersecting yarn flights in prescribed directions for imparting a rotational force to the first yarn run.
 2. The method as recited in claim 1, wherein the intersecting yarn flights are substantially normal to the first run of advancing yarn.
 3. The method of claim 1, wherein the yarn is directed in a selected pattern to form spaced series of intersecting yarn flights.
 4. The method as recited in claim 1, wherein the yarn flights intersect to form a triangle and the first yarn run passes through the triangle.
 5. The method of claim 3, wherein the spaced series of intersecting yarn flights apply rotational and longitudinal forces to the first run of yarn.
 6. The method of claim 1, and further applying a force longitudinally of the yarn downstream of yarn forming the selected pattern for directing the yarn through the selected pattern to impart a unidirectional rotation to the yarn forming the first run.
 7. An apparatus for applying a false twist to an advancing textile yarn comprising, support means, a plurality of elongated elements mounted in spaced, generally parallel relation upon said support means and each element having a surface region for frictionally contacting the yarn, means for directing an advancing yarn in a first run in spaced relation to and generally parallel to the axes of said elongated elements and for guiding the yarn from the first run in a path into contact with the surface region of one of said elongated elements, said elongated elements being selectively positioned such that yarn is directed thereabout in a plurality of yarn flights with the yarn flights intersecting to define a channel for passage of the first run of yarn, said first run of yarn being substantially normal to the yarn flights, and at least a plurality of yarn flights frictionally engaging the first yarn run to impart unidirectional rotary movement thereto upon advancement of the yarn directed about the elongated elements.
 8. An apparatus for applying a false twist to a yarn as recited in claim 7, wherein said elongated elements comprise freely rotatable rollers.
 9. An apparatus for applying a false twist to a textile yarn as recited in claim 8, wherein the surface region of each roller is provided with a plurality of yarn receiving annular grooves, said yarn being wound around said rollers to form a series of intersecting yarn flights.
 10. An apparatus for applying a false twist to a yarn as recited in claim 9, wherein the yarn progressively moves from the lowermost to the uppermost grooves of said rollers thereby facilitating longitudinal displacement of the yarn first run.
 11. An apparatus for applying a false twist to a yarn as recited in claim 7, wherein a plurality of advancing yarns are directed in spaced parallel runs and around said elongated elements with the intersecting yarn flights defining a plurality of channels, the yarn being received in each channel.
 12. An apparatus for applying a false twist to a yarn as recited in claim 11, wherein one yarn with a channel has an S twist applied by intersecting yarn flights and another yarn within a second channel has a Z twist applied thereto by intersecting yarn flights.
 13. An apparatus for applying a false twist to an advancing textile yarn as recited in claim 7, and further including means for applying a longitudinal force to the yarn for drawing the yarn about the elongated elements to impart a torque to the first run of yarn by said yarn flights. 